The Clinical Core (Core C) forms the central nexus of clinical, translational and patient sample-based interdisciplinary HIV research conducted by Penn CFAR investigators. Its central objective is to offer basic, translational, clinical, epidemiologic, and behavioral science investigators from multiple programmatic disciplines quick access to a broad range of epidemiologic data and clinical material from HIV infected individuals characterized in detail, as well as the identification of HIV infected individuals for recruitment into cross sectional or longitudinal studies. In support of this mission the Clinical Core provides CFAR investigators with: (1) an Adult/Adolescent Database comprised of nearly 3000 patients cared for at Penn-affiliated adult HIV practices at four hospitals and one adolescent (behaviorally infected) practice, and a Pediatric Database including longitudinal data on 275 perinatally infected children;(2) Adult/Adolescent and Pediatric Specimen Repositories linked to the Databases, (3) the capability to supply investigators with fresh patient material, including large volumes of cells collected by phlebotomy or apheresis, genital secretions, gastrointestinal lymph tissue and peripheral adiopose tissue biopsies, and cerebrospinal fluid;and (4) the use of laboratory support for the processing, storage, and shipment of clinical specimens. In addition, the Clinical Core (5) provides a mentoring structure for trainees and junior faculty. In the coming funding cycle we plan to expand these services to further support CFAR investigator needs. The Adult/Adolescent Database will be enlarged to include 4000 subjects. A focused recruitment of subjects for inclusion in the Specimen Repository will be conducted to expand the volume of patient material from HIV infected individuals with specific clinical phenotypes, including acute illness, effective control of virus replication in the absence of therapy, high viral loads off therapy, virologic failure, dual-tropic or mixtures of R5+X4 virus, and hepatitis coinfection. HIV uninfected individuals engaged in high risk behaviors will be recruited for a new initiative concentrating on the biology of HIV transmission. Effort will be expended to augment the portfolio of interdisciplinary research focused on women's health issues, the biology of HIV infection in the gastrointestinal tract, and science related to the development of an effective vaccine. The services provided by the Clinical Core will be evaluated annually to ensure that investigators'needs are met and utilization of the resources is maximized.